Help With Filter Set-up

I'm not sure if my question is about the filter or the air pump, as it all seems to be part of the same kit (it may just be a filter). I figured out how to set it up, but I'm not sure if the clear, rubber tube, which points up vertically from where it fixes to the filter pump, should be in the water or outside. It labelled as an air inlet tube, so I thought it ought to be outside, but I'm not really sure. Can anyone advise?

 

Could you show pictures?

 

 

Can anyone help?

 

The part that you’re holding connects to an air pump. It goes outside of the tank.

 

No need for an air pump, just keep the black knob out of the water and it will suck air. On most versions, you can turn the knob to adjust the air flow.

 

Oh perfect, I was worried that that part was supposed to be sucking up water rather than air! Thank you for helping